Everything is perfect, except for..

Hi there,

I would have loved to have some good news for you guys..
My story goes like this:

Last year in january, i bought a very nice stock 92'VFR750 with 80000km on the clock.
I got a motorcycle mechanic to check it out before chucking out the cash, and confirming popular wisdom, he said that it sounds and feels great for its age.

Did oil (10w40motul), filters, sparkplug changes at the correct moments.
Rode perfecty for 15000km, did not consume oil at all, did my 15km daily commute with it all the time, it started perfectly in the mornings, even in the cold 2 degree C ones (rode it alot during the winter).

Idle was a bit rough (+-50rpm) but not bothered about that, had in plan to synch carbs and do valves (maybe I should have done that sooner..)

One day after 50km of riding, engine was a bit hot, fan was still off, i heard beneath me a "clack-clack-clack; tap-tap" noise coming from the motor, maybe the lower part of it.Not sharp, dampened. Not constant, appearing every 5-10 seconds. Clutch lever did not affect it, nor gear position.
When the sound became audible, the rpm lowered for about 2 seconds then it was coming back...

Got scared. Stopped it. Called a mechanically empowered friend. He listened to it and bad news: "Crankshaft failure".

I don t know... When the engine is cold, you can not hear anything, it is perfect.
If it gets hot and then i kill it for 5 minutes, you can hear it quite loud.


I cannot believe this.. Do you think it is plausible? Are there any other possible causes?


Any help will bi highly appreciated!
Regards,
Bogdan

 

could be starter gear clutch, or clutch basket

 

drop the oil and look for large amounts of fine metal, indicating rod or main bearing failure. i would doubt that is the case